Design and Verification of a Fully Interchangeable Additively Manufactured Production Injector

The development of additively manufactured (AM) components via Powder Bed Fusion - Laser Beam (PBF-LB) has accelerated in recent years within the gas turbine industry. A desire to reduce manufacturing steps, assembly complexity, supply chain dependency, and development cycle time are all driven by efforts within the industry to reduce cost. At Solar Turbines®, AM technology development has focused on the design, print, and verification of AM injectors that can match the established performance of the legacy DLE production counterpart. The motivation for this focus is full interchangeability between the AM and non-AM produced injectors, allowing customers to either use existing injectors available off the shelf, on-demand AM produced injectors, or a combination of both. Accordingly, the team has recently designed, 3D printed, and verified an AM produced injector that matches the performance of the production DLE counterpart. Using in-house developed AM technology that is not constrained by the traditional AM design rule of a 45° build angle limit, AM was used to produce matching flow feature geometries that are otherwise very difficult to print with traditional AM methods. Key combustion parameters were also matched, such as fuel-air mixing profiles, velocity profiles, and combustion exit profiles. These parameters all play an important role in emissions performance, lifing of downstream turbine hardware, and impact the potential for encountering thermoacoustic oscillations during engine operation. Through rig and full-scale engine testing, the design team has verified the interchangeability of AM and non-AM injectors and demonstrated that equivalent performance and emissions capability can be achieved with AM produced injectors without the need to compromise due to the complexity of the design.